1. Field of the Invention
The present invention relates to an electroluminescent display. More particularly, the present invention relates to an electroluminescent display having a structure capable of controlling an amount of oxygen therein, thereby minimizing short circuits between pixels.
2. Description of the Related Art
An electroluminescent (EL) display is a flat display device where voltage may be applied to light emitting layers interposed between two electrodes to combine electrons and holes to form images. An EL display may have superior characteristics as compared to other display devices, such as excellent visibility, light weight, wide viewing angle, high color purity, and relative low power consumption.
A conventional EL display may include a substrate with a pixel region and a non-pixel region, a light emitting diode having two electrodes, i.e., a cathode and an anode, with light-emitting layers therebetween, a cap to seal the light emitting diode on the pixel region of the substrate, and an integrated circuit (IC) component to drive the EL display.
The cap may be attached to the substrate in an inert gas environment, e.g., nitrogen or argon, to form a sealed shell for the light emitting diode and, thereby, minimize contact thereof with air and moisture. Such minimized contact with air and moisture may reduce unfavorable effects of air and moisture on the electric characteristics and emission properties of the light emitting diode and, thereby, enhance the lifespan of the EL display. In particular, the cathode electrode of the light emitting diode may be made of metal and, thereby, be susceptible to oxidation due to contact with moisture. Similarly, if the light emitting layers of the light emitting diode are made of organic material, they may be susceptible to premature deterioration due to contact with hydrogen and oxygen.
During attachment of the cap to the substrate, a small amount of oxygen may be introduced into the interior of the sealed shell of the light emitting diode in order to prevent a short circuit between pixels therein. However, inaccurate control of the oxygen amount inside the sealed shell may be unfavorable. In particular, excess oxygen inside the sealed shell may advance contraction of the pixels. Alternatively, insufficient oxygen inside the sealed shell may cause short circuits between pixels therein. Even if the oxygen amount is appropriate at the time of the EL display formation, its quantity may be reduced overtime and, subsequently, may trigger short circuits.
Accordingly, there remains a need to provide an EL display having a structure capable of controlling the amount of oxygen therein in order to maintain its proper electrical operation.